What are you planning to charge, and what would your guarantee be? You aren't going to be digging up the park to install cabling, that isn't going to happen. The mess would be enough to stop me, but how many people have wired device connections in the first place? It sure wouldn't work with I phones, I pads, most Android pads etc. Where are you going to magically get the extra bandwidth from? My ISPs (I use two different ones) deliver 10 MBS down and 2.5 MBS up. That is all there is for up to 100+ users at a time. Can't get any more at any price (well I could I guess pay to run a fiber optic line 60 or so miles, probably cost a couple of million or so). That is what you would have to work with. Don't think that any network magician could make that backhaul carry 20 or 30 simultaneous Netflix HD streams.
If I was to pay for a service like you propose, I would have to have a guarantee that I would be getting value for the money spent. Since you have never done a park, you wouldn't have any references to check. Most park owners aren't very interested in spending a whole lot of money on the hope things will improve. Going to be a tough market.
